A hybrid energy recovery system is one wherein energy is recovered from a number of different energy sources located within a relatively small area such as, for example, the area surrounding and including the space occupied by a given architecture such as a house, apartment, factory, office building or a set of such buildings. Such a hybrid energy recovery system is known, for example, from: Russell Direct Gain Industrial Building Without Redundancy Has Quick Pay Back, proceedings of the Fifth National Passive Solar Conference, University of Delaware.
There is increasing agreement around the world that people would benefit from a change from nuclear fuels, coal, oil and gas as energy sources to clean indefinitely renewable and locally available natural energy sources such as sunshine, wind, and flowing water to generate useful electrical power. The use of each one of sunshine, wind and flowing water as an energy source by itself has its strengths and weaknesses, such as time of day or night, season, weather conditions, location of generators near to points of use, special land and directional and topographic requirements, the amount and cost of required real estate, aesthetic considerations, safety considerations, noise considerations, etc. However, when these natural and manmade sources of energy are used in combination to generate electrical power, they can go a long way in solving another major and heretofore expensive problem, namely that of providing a reasonably steady and continuous source of electricity for storage in batteries and other energy storage devices and/or for use in powering lamps, motors and other devices.
It is also important to local communities that the equipment required to convert natural energy sources to electricity be easy to manufacture and assemble, be easy to install, and be easy to service and replace when necessary by fully qualified local labor. This keeps the money to be spent in the community, and helps solve a current major worldwide problem occurring in many communities and nations of having to spend vast amounts of monies out of town or out of the nation to pay increasing prices for increasingly scarce and unhealthy non-renewable energy material such as nuclear fuel, oil, gas and coal.
Natural energy assets such as sun, wind, and flowing water can be considered as being of two types: (a) inherently natural, and (b) byproducts of human activities. For instance, we brightly light buildings to attract attention, parking lots to be safe, signs to be seen. This light is a byproduct of human activity and it is possible to recapture some of it with photovoltaic devices without interfering with the purpose for which the light was initially intended. As another example, it is possible for photovoltaic material to be carried on south facing highway noise barriers to pick up enough light from the headlights of passing trucks, buses and cars to supplement natural sunlight picked up by the photovoltaics during daytime. In the case of wind energy, thousands of trucks, buses, and cars driving down highways at high speed cause major gusts of wind which are often enhanced and channeled by land formations and noise barriers. A series of properly designed wind powered electrical generators can generate electricity from these gusts. In the case of flowing water power, large amounts of water run from hills or buildings when it rains, and this flowing water can be channeled and directed to small water wheel electrical generators at lower levels or into ponds that hold the water and release it when supplemental electrical power is needed.
High buildings in heavily built up areas can be cost free mounts for south facing photovoltaics to capture solar energy from the sun or can be used to channel wind or rain water to small wind powered or water powered electrical generators, and smaller flows of water can be combined and directed into larger flows to power turbines driving more powerful electrical generators.
From what has been said above, one can visualize a number of high buildings connected by glass enclosed walkways across streets, possibly at several levels. Some walls that face roughly south may have photovoltaic generating devices mounted on them. When wind is deflected from buildings causing areas of high wind velocity, this high wind velocity can be used by putting a series of small rotor type wind electrical generators between the two walkways which will deflect and increase the wind speed and electrical generation. Service could be made easy by access to the rotors through the ceiling of the lower walkway or the floor of the upper walkway.
In considering a system for combining the recovery of solar, wind, and water energy, it will be noted that solar energy recovery devices are leading the way with rapid technological breakthroughs. The efficiency of the devices are increasing and the prices of them are falling. Reasonably efficient and reasonably inexpensive water-powered generators are also available. The conversion of wind power into electrical energy is, however, the crucial element in a natural energy recovery system.
Wind energy has the potential to be the major energy provider of a recovery system, but suffers from clinging to natural wind resources only. The emphasis has been on natural wind and the few and costly sites that naturally have the necessary wind speeds. New developments have focused on complicated windmills of the propeller and Darrieus rotor technologies that supply high efficiency, but also have high initial expense, require high towers in most locations, are subject to expensive and dangerous servicing atop high towers, require a lot of space, cannot effectively utilize intermittent gusts (which is very wasteful), and can be destroyed by wind shears. These complicated windmills also require time to swing to face the quick changes in wind direction in the case of propeller-type units, and have uncertain stalling and starting problems in the case of Darrieus designs. Both propeller devices and Darrieus devices have niche applications where they do well, but these are limited.
Transporting electricity long distances is increasingly expensive and dangerous, and the source of most service interruptions and accidents. The new rules separating distribution from generation further camouflages costs that are already misleading because emergency costs often are paid by local police, fire departments, disaster organizations, and the Federal government. With remaining large monopolies, utility control boards are less effective, and individuals have little influence short of forming cooperative or generating their own power on site. Even small wind generating and photovoltaics can operate thermostats, pumps, and blowers to maintain critical heat and communications during protracted outages.
The Savonius rotor as a wind energy recovery device has long been used for such high torque applications as pumping water and grinding grain. It is a simple device which can, if well designed, use rotor units formed in one piece to very accurate standards and using new materials, with possibly self-lubricating properties that are recyclable and inexpensive. The rotor unit is then mounted on a vertical pipe or other support passing vertically through the center of the unit so that the unit revolves around the pipe when the wind blows onto the unit from any direction with sufficient velocity. That is, the Savonius rotor can use wind from any and all directions at all times. This simple two-bladed Savonius rotor, or similar rotors with three or more blades, operates at relatively low speeds in comparison to some other types of wind-powered rotors and has usually been considered to be inefficient for electric generating purposes, with efficient generation of electricity usually being considered to require higher rotor speeds than generally available from Savonius rotors.
The object of the present invention is, therefore, to provide a hybrid energy recovery system for recovering energy in electrical and/or mechanical form from a combination of solar, wind, and flowing water energy sources, both naturally occurring and man made.
A further more detailed object of the invention is to provide a Savonius-type rotor apparatus which can be used for generating electrical power from wind power and which generates efficiently at higher speeds of electrical power production than do conventional Savonius rotors, with such higher speeds of electrical power production being obtained without gears or other mechanical speed-increasing devices.
Another object of the invention is to provide a Savonius-type rotor apparatus of the above-mentioned kind which can also be used in the energy recovery system of the invention to recover electrical energy from the energy of flowing water, and which can also be used for recovery of solar energy, the Savonius rotor having a relatively large surface area in comparison to propellers and many other types of wind driven devices and, therefore, being well suited to additionally serve as a solar energy recovery device.